Many people are concerned about excess chemicals and pesticides in their immediate environment, made obvious by the increase in popularity of organically grown foods. Following an integrated pest management method or IPM at home will greatly reduce the amount of chemicals you need in your garden. For a more environmentally sound, organic approach IPM is the way to go.

 

Soil

As always, start with good soil. If you have not done so already incorporate up to one-third organic material like peat moss or compost. If you are applying aged manure on the vegetable garden it is best to do so in the fall, allowing it to break down over the winter and significantly reducing or eliminating any bacteria present in the manure. It also helps to add zeolite at rate of 20 kg per 10m2 or per 3533 ft2.

 

Plant Resistant Varieties

An easy way to avoid disease and fungus problems is to purchase resistant varieties. Many vegetables, flowers, bulbs, shrubs, and trees have been bred to resist certain problems. For example, some tomatoes are bred to resist fusarium wilt and verticillium wilt. The letters ‘VFN’ on their tags identifies these plants.

 

Rotate Crops

Of particular importance in reducing plant problems and subsequently reducing chemical use is crop rotation. If you grow a plant or a plant in the same family in the same area year after year disease-causing organisms can build up. In addition certain insects may lay their eggs in the fall in anticipation of a spring food source. It is best to cycle through three types of plants over three years. This will reduce the build up of disease organisms in the soil that affect specific plants. A sample crop rotation at one location would be tomatoes, peppers, and/or potatoes the first year, cauliflower and/or cabbage the next, and beans and/or peas the third year. This is only an example but be sure to check what family your plants belong to before rotation. Tomatoes and potatoes are in the same family (Solanacea) and alternating these crops does not help to prevent disease though it can help to a lesser degree with insect pests.

 

Controlling Pests

Check you plants once or twice a week. It is much easier to take care of a pest problem when it first appears. If you find any pest insects (remember not all insects are pests) or a fungus problem remove them by hand if possible. Pull weeds to reduce competition, increase airflow, and remove host plants for some insect pests. Handpick any large insects like caterpillars if they are in lower numbers. For small insects like aphids or spider mites a hard stream of water can dislodge them from the plant, knocking them to the ground and making them easy prey for ground beetles, centipedes, birds, or other predators. If this does not work try to use chemicals with a low toxicity/ low environmental impact. Though non-toxic or of low toxicity to ourselves, sprays like insecticidal soap or pyrethrins are extremely effective against soft-bodied insects. There are also fungicides like sulfur dust that are much safer to use than some chemicals. Do not forget that even though these pesticides are more environmentally friendly than others they are still pesticides; read and follow all label directions carefully. If all the above options fail then you can turn to synthetic pesticides and/or fungicides knowing you did your best to try other methods. Take care when using pesticides in the vegetable garden. Follow all instructions carefully – check how long you have to wait until they are safe to consume and, most importantly, if the plant you want to treat is not listed on the pesticide then that pesticide is not for that plant. You could damage the plant or harm yourself or both.

 

Biological Controls

It is important to recognize that not all insects are pests. Some are very helpful. Encourage ladybugs and their larvae to feed on aphid-infested plants. They can consume up to 300 aphids each per day. Lacewings and syrphid fly larvae are also excellent aphid controls. See our beneficial insect section for further information on the ‘good guys’ of the insect world. Wholesale spraying of strong chemicals will eliminate the beneficial insects, sometimes setting you up for a worse infestation in the long run since the natural control insects (present usually in much smaller numbers than the pest) have been destroyed in the area.

 

Take Good Care of Your Plants

A healthy plant almost always has an easier time resisting pests than an unhealthy one. Generally we keep our vegetable garden well-watered, free of weeds, and fertilized. The same holds true usually for the flower gardens be they perennial or annual. We tend to neglect, however, our trees and shrubs, both of which, but trees are commonly underwatered and undernourished. A good example of this in Calgary is the Birch. Birch trees need a lot of water and are often quite dry. This reduces their resistance to the leaf miner, which can do tremendous damage to the leaves. In addition, a weak birch will experience major winter dieback. Follow watering directions set out in our xeriscaping section and fertilize either with spikes or by hand watering 2-3 time per season but no fertilizing later than the last weekend of July. As a result, your birch will be stronger and more able to resist attack by leaf miner. The same basic principles apply for all trees and shrubs; a healthy plant tends to have less pest problems.

 

Accept a Few Insects

If all the above directions are followed and your plant still has a few pest insects it is best to simply accept it. This is especially true of trees and shrubs. A tree is an ecosystem unto itself. It has evolved to support minor pest populations. Trees, depending on the variety, can even handle one or two years of total defoliation by insects before running into major trouble. If it is not bothering the plant, do not let it bother you. Granted, in the case of vegetables and prize perennials it can be frustrating and may warrant control methods. However, if you find that a particular type of plant under good growing conditions still seems to attract aphids to your yard, it may be best to simply remove it for the sake of your other plants.